Time - one of the basic concepts in philosophy and physics, the conditional measure of the relative motion of matter, as well as one of the coordinates of space-time, along which the world lines of physical bodies are stretched.
In quantitative (metrological) sense concept of time has three dimensions:
- coordinates of the event on the time axis. This is current time: calendar, defined by the calendar rules, and time of day, determined by a calculation system (scale) of time (examples: local time, Coordinated Universal Time).
- relative time interval between two events.
- subjective parameter when comparing several different frequency processes.